The present invention concerns a method of fastening two or more components together by rivets. The invention also concerns a device for carrying out the aforesaid method. Sheet metal components, especially those riveted together, are now being increasingly employed in the field of automotive manufacture. This trend has been augmented by the practice of combining various components into subassemblies. Riveted joints can also be reinforced with adhesives.
U-shaped “tongs” with a rivet driver at the end of one arm and a dolly at the end of the other are often employed to rivet the parts together. Such tongs can be operated by hand or by robots. Since the rivets usually are of types that punch their own holes out of the material, no preliminary punching is necessary.
The aforesaid method, which employs hydraulically or electrically powered tongs, has several drawbacks. The arms of the tongs must be very rigid, and their weight accordingly increases considerably with their length, with how far the riveting point is from the outer edge of the component, that is. Such tongs are very heavy, and their arms tend to sag considerably. The robots need to be very sturdy, and cannot move as quickly as lighter-weight robots.
Another disadvantage is low speed. The tongs have to be opened and, in a complicated procedure, correctly positioned before they can be shifted to the next riveting point. This procedure can be even more troublesome when the machinery includes several robots and several riveting tongs.